jeteve has asked for the wisdom of the Perl Monks concerning the following question:

Fellow Monks,

I'm playing with Crypt::OpenPGP and I think I'm starting to loose my sanity. No matter how hard I try, I always end up by having some error from the PARI lib when I decrypt.

Here's my test script (shamelessly taken from this site #522597):

#!/usr/bin/perl
use strict;
use warnings;

# generate public/private Crypt::OpenPGP keys.
# encrypt some data
# decrypt some data

use Crypt::OpenPGP;

my $size  = 1024;
my $ident = 'Me <me@example.com>';
my $pass  = 'my passphrase';
my $public_file  = 'public.pgp';
my $private_file = 'private.pgp';

my $keychain = Crypt::OpenPGP->new;

my ($public, $private) = $keychain->keygen (
                                             Type => 'RSA',
                                             Size      => $size,
                                             Identity  => $ident,
                                             Passphrase  => $pass,
                                             Verbosity => 1,
                                           ) or die $keychain->errstr(
+);
my $public_str = $public->save;
my $private_str = $private->save;

print "Public encrypting_key: ".$public->encrypting_key ."\n";
print "Private encrypting_key: ".$private->encrypting_key ."\n";

open( PUB, '>', $public_file ) or die $!;
  print PUB $public_str;
close(PUB);

open( PRIV, '>', $private_file ) or die $!;
  print PRIV $private_str;
close(PRIV);

my $pgp = Crypt::OpenPGP->new( PubRing => $public_file );
my $cyphertext = $pgp->encrypt ( Data    => 'Encrypt This',
                                 Recipients => $ident,
                                 Armour     => 1,
                               ) || die $pgp->errstr();
print $cyphertext;

$pgp = new Crypt::OpenPGP( SecRing => $private_file );
my $plaintext = $pgp->decrypt (
                               Data => $cyphertext,
                               Passphrase => $pass,
                              ) || die $pgp->errstr();

print "plaintext: $plaintext\n";

[download]

It invariably ends with:

PARI:   ***   unexpected character: 
                                   ^-

Note that I've got the latest version of Crypt::OpenPGP from github, and that all the unit test pass very happily.

I must be going something very wrong. Thanks in advance for your help.

-- Jerome Eteve

Replies are listed 'Best First'.
Re: Crypt OpenPGP Brain twister
by Khen1950fx (Canon) on Jun 21, 2011 at 17:24 UTC
    print "plaintext: $plaintext\n"

    That seems to be the major stumbling block. I tried it, and it came back undef each time, "undef" meaning failure. So I put together this example from the docs.

    First, we need to create a plaintext data packet object and serialize that object. Next, deserialize the object.

    I used Crypt::OpenPGP::Plaintext. 

    #!/usr/bin/perl

use strict;
use warnings;
use Crypt::OpenPGP::Plaintext;
use Data::Dumper::Concise;

my $data = 'foo bar';
my $file = '/root/Desktop/foo.txt';

my $pt = Crypt::OpenPGP::Plaintext->new(
                   Data => $data,
                   Filename => $file,
                   Mode => 'b',
);
binmode STDOUT, ':encoding(utf8)';

print Dumper(my $serialized = $pt->save);
print Dumper($serialized = $pt->data);

    [download]
[reply]
[d/l]
      Um, its the decrypt call that is failing
[reply]
        jeteve or others: Did this ever get a resolution? I'm repeating the same error on the decode. What to do?
[reply]
      I've been struggling with this error myself.
      Problem is the keys generated by ->keygen were crap.
      My solution was to get some keys generated the "proper" way, and that worked perfectly.
[reply]
        How do we generate the key in "proper" way?
[reply]
Re: Crypt OpenPGP Brain twister
by Anonymous Monk on Jun 21, 2011 at 01:13 UTC
    It invariably ends with:

    Which method call generates that error?

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